1. If the original owner of the property is reported to have died intestate and he is reported to have been an unmarried person, then his successor in interest would be the lone surviving class I legal heir, i.e., his mother, hence there is no legal infirmity in society transferring his share certificate to his mother's name.
She can get the property transferred to her name by producing the death certificate and legal heirship certificate after which she can sell the property in favor of any prospective buyer as an absolute owner with clear and marketable title to the property.
2.No, not at least during the lifetime of his mother.
3. You better get a legal opinion from a local lawyer before venturing into this purchase.